This invention relates to an oscillatory driving circuit and more particularly to a circuit for providing oscillatory drive signals for a mechanically mounted member to remove initial static friction therefrom.
Initial or static friction has long been a problem in the field of precision transducers for sensing physical quantities such as displacement, velocity, and acceleration due to the initial errors induced by static friction in the instrument assembly. Various schemes for overcoming the static friction errors have been introduced, including mechanical buzzers, destabilization of feedback, or application of oscillatory inputs at the initial power application by circuitry which is hard wired into the remainder of the transducer circuitry. The latter circuitry requires continuous power drain which is often times unacceptable. The mechanical buzzer generally requires relatively high power levels as well as presenting a reliability problem which is a function of the environment to which the transducer is exposed. Feedback loop destabilization presents the possibility of an additional failure mode in nonoperation or in continuing operation of the destabilizaton and is therefore objectionable for some applications. A means for providing driving signals for a short period of time after application of power is needed which requires minimal power drain subsequent to the short period of time, which presents no reliability problem from malfunction and which is insensitive to environmental change.